Re: Maximize page freezing

On Fri, 29 Jul 2022 at 16:38, Simon Riggs <simon(dot)riggs(at)enterprisedb(dot)com> wrote:
>
> On Thu, 28 Jul 2022 at 14:55, Matthias van de Meent
> <boekewurm+postgres(at)gmail(dot)com> wrote:
> > Great idea, yet this patch seems to only freeze those tuples that are
> > located after the first to-be-frozen tuple. It should probably
> > re-visit earlier live tuples to potentially freeze those as well.
>
> Like this?

That wasn't quite what I imagined. In your patch, heap_page_prune is
disabled after the first frozen tuple, which makes the retry mechanism
with the HTSV check loop forever because it expects that tuple to be
vacuumed.

I was thinking more in the line of "do a backtrack in a specialized
code block when entering max_freeze_page mode" (without using
'retry'), though I'm not sure whether that's the best option
available.

Kind regards,

Matthias van de Meent